The increasing use of engineered organisms for industrial, clinical, and environmental applications poses a growing risk of spreading hazardous biological entities into the environment. To address this biosafety issue, significant effort has been invested in creating ways to confine these organisms and transgenic materials. Emerging technologies in synthetic biology involving genetic circuit engineering, genome editing, and gene expression regulation have led to the development of novel biocontainment systems...

The Johns Hopkins Hospital created a biocontainment unit (BCU) to care for patients with highly infectious diseases while assuring healthcare worker safety. Research to date for BCU protocols and practices are based on case reports and lessons learned from patient care and exercises. This study seeks to be the first to explore the influences of healthcare worker movement and personal protective equipment (PPE) doffing on the transport of simulant pathogen particles in a BCU. A cough device released 1 μm fluorescent polystyrene beads (PSLs) in the patient room...

Zoonotic viruses circulate as swarms in animal reservoirs and can emerge into human populations, causing epidemics that adversely affect public health. Portable, safe, and effective vaccine platforms are needed in the context of these outbreak and emergence situations. In this work, we report the generation and characterization of an alphavirus replicon vaccine platform based on a non-select agent, attenuated Venezuelan equine encephalitis (VEE) virus vaccine, strain 3526 (VRP 3526). Using both noroviruses and coronaviruses as model systems, we demonstrate the utility of the VRP 3526 platform in the generation of recombinant proteins, production of virus-like particles, and in vivo efficacy as a vaccine against emergent viruses...

We propose the idea of "phenotype diffusion," which is a rapid convergence of an observed trait in some human and animal populations. The words phenotype and diffusion both imply observations independent of mechanism as phenotypes are observed traits with multiple possible genetic mechanisms and diffusion is an observed state of being widely distributed. Recognizing shared changes in phenotype in multiple species does not by itself reveal a particular mechanism such as a shared exposure, shared adaptive need, particular stochastic process or a transmission pathway...

Severe combined immunodeficiency (SCID) is defined by the lack of an adaptive immune system. Mutations causing SCID are found naturally in humans, mice, horses, dogs, and recently in pigs, with the serendipitous discovery of the Iowa State University SCID pigs. As research models, SCID animals are naturally tolerant of xenotransplantation and offer valuable insight into research areas such as regenerative medicine, cancer therapy, as well as immune cell signaling mechanisms. Large-animal biomedical models, particularly pigs, are increasingly essential to advance the efficacy and safety of novel regenerative therapies on human disease...

Incorporation of nonstandard amino acids (nsAAs) leads to chemical diversification of proteins, which is an important tool for the investigation and engineering of biological processes. However, the aminoacyl-tRNA synthetases crucial for this process are polyspecific in regard to nsAAs and standard amino acids. Here, we develop a quality control system called "posttranslational proofreading" to more accurately and rapidly evaluate nsAA incorporation. We achieve this proofreading by hijacking a natural pathway of protein degradation known as the N-end rule, which regulates the lifespan of a protein based on its amino-terminal residue...

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals and is endemic in Africa, parts of South America and southern Asia. The causative agent, FMD virus (FMDV) is a member of the genus Aphthovirus, family Picornaviridae. Vaccines currently used against FMDV are chemically inactivated virus strains which are produced under high-level biocontainment facilities, thus raising their cost. The development of recombinant FMDV vaccines has focused predominantly on FMDV virus-like particle (VLP) subunit vaccines for which promising results have been achieved...

Biocontaining during the recent Ebola outbreak served to affirm the social significance of biomedicine, even though it had little measurable effect on the pandemic itself. Taking up key insights of Mary Douglas and Victor Turner concerning the essential meaning-making tasks of culture, this article discusses how biocontaining as an activity contributed to the work of social reassurance and meaning-making in U.S. and global society during the crisis. The analysis is based in significant part on fieldwork done at the Nebraska Biocontainment Unit (NBU), study of NBU educational materials, and follow-up conversations with personnel staffing that unit...

Controlling the exchange of genetic information between sexually reproducing populations has applications in agriculture, eradication of disease vectors, control of invasive species, and the safe study of emerging biotechnology applications. Here we introduce an approach to engineer a genetic barrier to sexual reproduction between otherwise compatible populations. Programmable transcription factors drive lethal gene expression in hybrid offspring following undesired mating events. As a proof of concept, we target the ACT1 promoter of the model organism Saccharomyces cerevisiae using a dCas9-based transcriptional activator...

Full genome recoding, or rewriting codon meaning, through chemical synthesis of entire bacterial chromosomes has become feasible in the past several years. Recoding an organism can impart new properties including non-natural amino acid incorporation, virus resistance, and biocontainment. The estimated cost of construction that includes DNA synthesis, assembly by recombination, and troubleshooting, is now comparable to costs of early stage development of drugs or other high-tech products. Here, we discuss several recently published assembly methods and provide some thoughts on the future, including how synthetic efforts might benefit from the analysis of natural recoding processes and organisms that use alternative genetic codes...

As the world increasingly relies on aquaculture operations to meet rising seafood demands, reliable biocontainment measures for farmed fish stocks are desired to minimize ecological impacts arising from interactions of cultured fish with wild populations. One possible biocontainment strategy is to induce a dietary dependence on a vitamin, such as thiamine (vitamin B1), required for survival. Fish expressing thiaminase (an enzyme that degrades thiamine) within a confined aquaculture facility could receive supplemental thiamine to allow survival and normal growth, whereas escapees lacking this dietary rescue would die from thiamine deficiency...

The gut microbiome plays a crucial role in maintaining human health. Functions performed by gastrointestinal microbes range from regulating metabolism to modulating immune and nervous system development. Scientists have attempted to exploit this importance through the development of engineered probiotics that are capable of producing and delivering small molecule therapeutics within the gut. However, existing synthetic probiotics are simplistic and fail to replicate the complexity and adaptability of native homeostatic mechanisms...

The implementation of biosecurity measures in the animal health and production context is quite broad and aims at limiting the risk of introduction and spread of diseases. Veterinarians play a major role in biosecurity as key informants on the subject for cattle holders, key players in terms of disease prevention/control and eradication programs, as well as key risk factor in terms of disease dissemination. Many biosecurity studies have highlighted professional visitors such as veterinary practitioners as representing a high-risk factor in terms of disease introduction in animal facilities but, to date, very few studies have focused on the implementation level of biosecurity measures by veterinarians...

The Ebola outbreak of 2014-2016 highlighted the need for the development of a more robust healthcare infrastructure in the United States to provide isolation care for patients infected with a highly hazardous contagious disease. Routine exercises and skills practice are required to effectively and safely prepare care teams to confidently treat this special population of patients. The Nebraska Biocontainment Unit (NBU) at Nebraska Medicine in Omaha has been conducting exercises since 2005 when the unit was opened...

Usable pollination control systems have proven to be effective system for the development of hybrid crop varieties, which are important for optimal performance over varied environments and years. They also act as a biocontainment to check horizontal transgene flow. In the last two decades, many genetic manipulations involving genes controlling the production of cytotoxic products, conditional male sterility, altering metabolic processes, post-transcriptional gene silencing, RNA editing and chloroplast engineering methods have been used to develop a proper pollination control system...

Biocontainment systems are crucial for preventing genetically modified organisms from escaping into natural ecosystems. Here, we describe the orthogonal ribosome biofirewall, which consists of an activation circuit and a degradation circuit. The activation circuit is a genetic AND gate based on activation of the encrypted pathway by the orthogonal ribosome in response to specific environmental signals. The degradation circuit is a genetic NOT gate with an output of I-SceI homing endonuclease, which conditionally degrades the orthogonal ribosome genes...

The recent Ebola virus disease outbreak highlighted the need to build national and worldwide capacity to provide care for patients with highly infectious diseases. Specialized biocontainment units were successful in treating several critically ill patients with Ebola virus disease both in the United States and Europe. Several key principles underlie the care of critically ill patients in a high-containment environment. Environmental factors, staffing, equipment, training, laboratory testing, procedures, and waste management each present unique challenges...

Transmission electron microscopy (TEM) is used to observe the ultrastructure of viruses and other microbial pathogens with nanometer resolution. Most biological materials do not contain dense elements capable of scattering electrons to create an image; therefore, a negative stain, which places dense heavy metal salts around the sample, is required. In order to visualize viruses in suspension under the TEM they must be applied to small grids coated with a transparent surface only nanometers thick. Due to their small size and fragility, these grids are difficult to handle and easily moved by air currents...

Surrogate microorganisms, in short surrogates, are an essential part of pathogen research. Compared to surrogates used in controlled laboratory environments, surrogates for field release are restricted by concerns about human and environmental safety. For field research of food-borne pathogens, strains of an attenuated pathogen or strains of genetically close non-pathogenic species have been used as surrogates. Genetic modification is usually performed to attenuate virulence, through for examples deletion of genes of virulence and transcriptional regulators and removal of virulence plasmids, and to facilitate detection and monitoring through observing antibiotic resistance, fluorescence, and bioluminescence...